Remove unused dependency

1 files changed, 0 insertions, 499 deletions

diff --git a/external/glim/mdb.hpp b/external/glim/mdb.hpp
deleted file mode 100644
index eca66f37d..000000000
--- a/external/glim/mdb.hpp
+++ /dev/null
@@ -1,499 +0,0 @@
-#ifndef _GLIM_MDB_HPP_INCLUDED

-#define _GLIM_MDB_HPP_INCLUDED

-

-/**

- * A C++ wrapper around MDB (http://www.symas.com/mdb/).

- * @code

-Copyright 2012 Kozarezov Artem Aleksandrovich

-

-Licensed under the Apache License, Version 2.0 (the "License");

-you may not use this file except in compliance with the License.

-You may obtain a copy of the License at

-

-    http://www.apache.org/licenses/LICENSE-2.0

-

-Unless required by applicable law or agreed to in writing, software

-distributed under the License is distributed on an "AS IS" BASIS,

-WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

-See the License for the specific language governing permissions and

-limitations under the License.

- * @endcode

- * @file

- */

-

-#include <mdb.h>

-#include <boost/archive/binary_oarchive.hpp>

-#include <boost/archive/binary_iarchive.hpp>

-#include <boost/serialization/serialization.hpp>

-#include <boost/noncopyable.hpp>

-#include <boost/iterator/iterator_facade.hpp>

-#include <boost/range/iterator_range.hpp>

-

-#include <arpa/inet.h> // htonl, ntohl

-

-#include "gstring.hpp"

-

-namespace glim {

-

-struct MdbEx: public std::runtime_error {MdbEx (std::string message): std::runtime_error (message) {}};

-

-template <typename T> inline void mdbSerialize (gstring& bytes, const T& data) {

-  gstring_stream stream (bytes);

-  boost::archive::binary_oarchive oa (stream, boost::archive::no_header);

-  oa << data;

-}

-template <typename V> inline void mdbDeserialize (const gstring& bytes, V& data) {

-  gstring_stream stream (const_cast<gstring&> (bytes));

-  boost::archive::binary_iarchive ia (stream, boost::archive::no_header);

-  ia >> data;

-}

-

-/** uint32_t keys are stored big-endian (network byte order) in order to be compatible with lexicographic ordering. */

-template <> inline void mdbSerialize<uint32_t> (gstring& bytes, const uint32_t& ui) {

-  uint32_t nui = htonl (ui); bytes.append ((const char*) &nui, sizeof (uint32_t));}

-/** Deserialize uint32_t from big-endian (network byte order). */

-template <> inline void mdbDeserialize<uint32_t> (const gstring& bytes, uint32_t& ui) {

-  if (bytes.size() != sizeof (uint32_t)) throw MdbEx ("Not uint32_t, wrong number of bytes");

-  uint32_t nui = * (uint32_t*) bytes.data(); ui = ntohl (nui);}

-

-/** If the data is `gstring` then use the data's buffer directly, no copy. */

-template <> inline void mdbSerialize<gstring> (gstring& bytes, const gstring& data) {

-  bytes = gstring (0, (void*) data.data(), false, data.length());}

-/** Deserializing into `gstring` copies the bytes into it, reusing its buffer. */

-template <> inline void mdbDeserialize<gstring> (const gstring& bytes, gstring& data) {

-  data.clear() << bytes;}

-

-/**

- * Header-only C++ wrapper around OpenLDAP-MDB.\n

- * Uses Boost Serialization to pack keys and values (glim::gstring can be used for raw bytes).\n

- * Allows semi-automatic indexing with triggers.\n

- * Known issues: http://www.openldap.org/its/index.cgi?findid=7448

- */

-struct Mdb {

-  std::shared_ptr<MDB_env> _env;

-  MDB_dbi _dbi = 0;

-

-  typedef std::unique_ptr<MDB_txn, void(*)(MDB_txn*)> Transaction;

-

-  /** Holds the current key and value of the Iterator. */

-  struct IteratorEntry {

-    MDB_val _key = {0, 0}, _val = {0, 0};

-    /** Zero-copy view of the current key bytes. Should *not* be used after the Iterator is changed or destroyed. */

-    const gstring keyView() const {return gstring (0, _key.mv_data, false, _key.mv_size, true);} // Zero copy.

-    /** Zero-copy view of the current value bytes. Should *not* be used after the Iterator is changed or destroyed. */

-    const gstring valueView() const {return gstring (0, _val.mv_data, false, _val.mv_size, true);} // Zero copy.

-    /** Deserialize into `key`. */

-    template <typename T> void getKey (T& key) const {mdbDeserialize (keyView(), key);}

-    /** Deserialize the key into a temporary and return it. */

-    template <typename T> T getKey() const {T key; getKey (key); return key;}

-    /** Deserialize into `value`. */

-    template <typename T> void getValue (T& value) const {mdbDeserialize (valueView(), value);}

-    /** Deserialize the value into a temporary and return it. */

-    template <typename T> T getValue() const {T value; getValue (value); return value;}

-  };

-  /** Holds the Iterator's unique transaction and cursor, allowing the Iterator to be copied. */

-  struct IteratorImpl: boost::noncopyable {

-    Mdb* _mdb;

-    Transaction _txn;

-    MDB_cursor* _cur;

-    IteratorImpl (Mdb* mdb, Transaction&& txn, MDB_cursor* cur): _mdb (mdb), _txn (std::move (txn)), _cur (cur) {}

-    ~IteratorImpl() {

-      if (_cur) {::mdb_cursor_close (_cur); _cur = nullptr;}

-      if (_mdb && _txn) {_mdb->commitTransaction (_txn); _mdb = nullptr;}

-    }

-  };

-  /** Wraps MDB cursor and cursor's transaction. */

-  struct Iterator: public boost::iterator_facade<Iterator, IteratorEntry, boost::bidirectional_traversal_tag> {

-    std::shared_ptr<IteratorImpl> _impl; // Iterator might be copied around, thus we keep the unique things in IteratorImpl.

-    IteratorEntry _entry;

-    bool _stayInKey = false;

-

-    Iterator (const Iterator&) = default;

-    Iterator (Iterator&&) = default;

-    /** Iterate from the beginning or the end of the database.

-     * @param position can be MDB_FIRST or MDB_LAST */

-    Iterator (Mdb* mdb, int position = 0): _stayInKey (false) {

-      Transaction txn (mdb->beginTransaction());

-      MDB_cursor* cur = nullptr; int rc = ::mdb_cursor_open (txn.get(), mdb->_dbi, &cur);

-      if (rc) throw MdbEx ("mdb_cursor_open");

-      _impl = std::make_shared<IteratorImpl> (mdb, std::move (txn), cur);

-      if (position == ::MDB_FIRST || position == ::MDB_LAST) {

-        rc = ::mdb_cursor_get (cur, &_entry._key, &_entry._val, (MDB_cursor_op) position);

-        if (rc) throw MdbEx ("mdb_cursor_get");

-      }

-    }

-    /** Iterate over `key` values.

-     * @param stayInKey if `false` then iterator can go farther than the `key`. */

-    Iterator (Mdb* mdb, const gstring& key, bool stayInKey = true): _stayInKey (stayInKey) {

-      Transaction txn (mdb->beginTransaction());

-      MDB_cursor* cur = nullptr; int rc = ::mdb_cursor_open (txn.get(), mdb->_dbi, &cur);

-      if (rc) throw MdbEx ("mdb_cursor_open");

-      _impl = std::make_shared<IteratorImpl> (mdb, std::move (txn), cur);

-      _entry._key = {key.size(), (void*) key.data()};

-      rc = ::mdb_cursor_get (cur, &_entry._key, &_entry._val, ::MDB_SET_KEY);

-      if (rc == MDB_NOTFOUND) {_entry._key = {0, 0}; _entry._val = {0, 0};}

-      else if (rc) throw MdbEx ("mdb_cursor_get");

-    }

-

-    struct EndIteratorFlag {};

-    /** The "end" iterator does not open an MDB transaction (this is essential for having a pair of iterators without a deadlock). */

-    Iterator (EndIteratorFlag): _stayInKey (false) {}

-    /** True if the iterator isn't pointing anywhere. */

-    bool end() const {return _entry._key.mv_size == 0;}

-

-    bool equal (const Iterator& other) const {

-      IteratorImpl* impl = _impl.get();

-      if (mdb_cmp (impl->_txn.get(), impl->_mdb->_dbi, &_entry._key, &other._entry._key)) return false;

-      if (mdb_dcmp (impl->_txn.get(), impl->_mdb->_dbi, &_entry._val, &other._entry._val)) return false;

-      return true;

-    }

-    IteratorEntry& dereference() const {

-      // NB: Boost iterator_facade expects the `dereference` to be a `const` method.

-      //     I guess Iterator is not modified, so the `dereference` is `const`, even though the Entry can be modified.

-      return const_cast<IteratorEntry&> (_entry);}

-    void increment() {

-      int rc = ::mdb_cursor_get (_impl->_cur, &_entry._key, &_entry._val, _stayInKey ? ::MDB_NEXT_DUP : ::MDB_NEXT);

-      if (rc) {_entry._key = {0,0}; _entry._val = {0,0};}

-    }

-    void decrement() {

-      int rc = ::mdb_cursor_get (_impl->_cur, &_entry._key, &_entry._val, _stayInKey ? ::MDB_PREV_DUP : ::MDB_PREV);

-      if (rc) {_entry._key = {0,0}; _entry._val = {0,0};}

-    }

-  };

-  Iterator begin() {return Iterator (this, ::MDB_FIRST);}

-  const Iterator end() {return Iterator (Iterator::EndIteratorFlag());}

-  /** Position the cursor at the first `key` record.\n

-   * The iterator increment will use `MDB_NEXT_DUP`, staying withing the `key`.\n

-   * See also the `all` method. */

-  template <typename K> Iterator values (const K& key) {

-    char kbuf[64]; // Allow up to 64 bytes to be serialized without heap allocations.

-    gstring kbytes (sizeof (kbuf), kbuf, false, 0);

-    mdbSerialize (kbytes, key);

-    return Iterator (this, kbytes);

-  }

-  /** Range over the `key` values.\n

-   * See also the `all` method. */

-  template <typename K> boost::iterator_range<Iterator> valuesRange (const K& key) {return boost::iterator_range<Iterator> (values (key), end());}

-

-  struct Trigger {

-    virtual gstring getTriggerName() const {return C2GSTRING ("defaultTriggerName");};

-    virtual void add (Mdb& mdb, void* key, gstring& kbytes, void* value, gstring& vbytes, Transaction& txn) = 0;

-    virtual void erase (Mdb& mdb, void* key, gstring& kbytes, Transaction& txn) = 0;

-    virtual void eraseKV (Mdb& mdb, void* key, gstring& kbytes, void* value, gstring& vbytes, Transaction& txn) = 0;

-  };

-  std::map<gstring, std::shared_ptr<Trigger>> _triggers;

-

-  void setTrigger (std::shared_ptr<Trigger> trigger) {

-    _triggers[trigger->getTriggerName()] = trigger;

-  }

-

-  /** `flags` can be `MDB_RDONLY` */

-  Transaction beginTransaction (unsigned flags = 0) {

-    MDB_txn* txn = 0; int rc = ::mdb_txn_begin (_env.get(), nullptr, flags, &txn);

-    if (rc) throw MdbEx (std::string ("mdb_txn_begin: ") + ::strerror (rc));

-    return Transaction (txn, ::mdb_txn_abort);

-  }

-  void commitTransaction (Transaction& txn) {

-    int rc = ::mdb_txn_commit (txn.get());

-    txn.release(); // Must prevent `mdb_txn_abort` from happening (even if rc != 0).

-    if (rc) throw MdbEx (std::string ("mdb_txn_commit: ") + ::strerror (rc));

-  }

-

-  virtual unsigned envFlags (uint8_t sync) {

-    unsigned flags = MDB_NOSUBDIR;

-    if (sync < 1) flags |= MDB_NOSYNC; else if (sync < 2) flags |= MDB_NOMETASYNC;

-    return flags;

-  }

-  /** Used before `mdb_env_open`. By default sets the number of database to 32. */

-  virtual void envConf (MDB_env* env) {

-    int rc = ::mdb_env_set_maxdbs (env, 32);

-    if (rc) throw MdbEx (std::string ("envConf: ") + ::strerror (rc));

-  }

-  virtual void dbFlags (unsigned& flags) {}

-

- protected:

-  void open (const char* dbName, bool dup) {

-    auto txn = beginTransaction();

-    unsigned flags = MDB_CREATE;

-    if (dup) flags |= MDB_DUPSORT;

-    dbFlags (flags);

-    int rc = ::mdb_open (txn.get(), dbName, flags, &_dbi);

-    if (rc) throw MdbEx (std::string ("mdb_open (") + dbName + "): " + ::strerror (rc));

-    commitTransaction (txn);

-  }

- public:

-

-  /** Opens MDB environment and MDB database. */

-  Mdb (const char* path, size_t maxSizeMb = 1024, const char* dbName = "main", uint8_t sync = 0, bool dup = true, mode_t mode = 0660) {

-    MDB_env* env = 0; int rc = ::mdb_env_create (&env);

-    if (rc) throw MdbEx (std::string ("mdb_env_create: ") + ::strerror (rc));

-    _env.reset (env, ::mdb_env_close);

-    rc = ::mdb_env_set_mapsize (env, maxSizeMb * 1024 * 1024);

-    if (rc) throw MdbEx (std::string ("mdb_env_set_mapsize: ") + ::strerror (rc));

-    envConf (env);

-    rc = ::mdb_env_open (env, path, envFlags (sync), mode);

-    _dbi = 0; open (dbName, dup);

-  }

-

-  /** Opens MDB database in the provided environment. */

-  Mdb (std::shared_ptr<MDB_env> env, const char* dbName, bool dup = true): _env (env), _dbi (0) {

-    open (dbName, dup);

-  }

-

-  template <typename K, typename V> void add (const K& key, const V& value, Transaction& txn) {

-    char kbuf[64]; // Allow up to 64 bytes to be serialized without heap allocations.

-    gstring kbytes (sizeof (kbuf), kbuf, false, 0);

-    mdbSerialize (kbytes, key);

-    MDB_val mkey = {kbytes.size(), (void*) kbytes.data()};

-

-    char vbuf[64]; // Allow up to 64 bytes to be serialized without heap allocations.

-    gstring vbytes (sizeof (vbuf), vbuf, false, 0);

-    mdbSerialize (vbytes, value);

-    MDB_val mvalue = {vbytes.size(), (void*) vbytes.data()};

-

-    for (auto& trigger: _triggers) trigger.second->add (*this, (void*) &key, kbytes, (void*) &value, vbytes, txn);

-

-    int rc = ::mdb_put (txn.get(), _dbi, &mkey, &mvalue, 0);

-    if (rc) throw MdbEx (std::string ("mdb_put: ") + ::strerror (rc));

-  }

-  template <typename K, typename V> void add (const K& key, const V& value) {

-    Transaction txn (beginTransaction());

-    add (key, value, txn);

-    commitTransaction (txn);

-  }

-

-  template <typename K, typename V> bool first (const K& key, V& value, Transaction& txn) {

-    char kbuf[64]; // Allow up to 64 bytes to be serialized without heap allocations.

-    gstring kbytes (sizeof (kbuf), kbuf, false, 0);

-    mdbSerialize (kbytes, key);

-    MDB_val mkey = {kbytes.size(), (void*) kbytes.data()};

-    MDB_val mvalue;

-    int rc = ::mdb_get (txn.get(), _dbi, &mkey, &mvalue);

-    if (rc == MDB_NOTFOUND) return false;

-    if (rc) throw MdbEx (std::string ("mdb_get: ") + ::strerror (rc));

-    gstring vstr (0, mvalue.mv_data, false, mvalue.mv_size);

-    mdbDeserialize (vstr, value);

-    return true;

-  }

-  template <typename K, typename V> bool first (const K& key, V& value) {

-    Transaction txn (beginTransaction (MDB_RDONLY));

-    bool rb = first (key, value, txn);

-    commitTransaction (txn);

-    return rb;

-  }

-

-  /** Iterate over `key` values until `visitor` returns `false`. Return the number of values visited. */

-  template <typename K, typename V> int32_t all (const K& key, std::function<bool(const V&)> visitor, Transaction& txn) {

-    char kbuf[64]; // Allow up to 64 bytes to be serialized without heap allocations.

-    gstring kbytes (sizeof (kbuf), kbuf, false, 0);

-    mdbSerialize (kbytes, key);

-    MDB_val mkey = {kbytes.size(), (void*) kbytes.data()};

-

-    MDB_cursor* cur = 0; int rc = ::mdb_cursor_open (txn.get(), _dbi, &cur);

-    if (rc) throw MdbEx (std::string ("mdb_cursor_open: ") + ::strerror (rc));

-    std::unique_ptr<MDB_cursor, void(*)(MDB_cursor*)> curHolder (cur, ::mdb_cursor_close);

-    MDB_val mval = {0, 0};

-    rc = ::mdb_cursor_get (cur, &mkey, &mval, ::MDB_SET_KEY); if (rc == MDB_NOTFOUND) return 0;

-    if (rc) throw MdbEx (std::string ("mdb_cursor_get: ") + ::strerror (rc));

-

-    V value;

-    gstring vstr (0, mval.mv_data, false, mval.mv_size);

-    mdbDeserialize (vstr, value);

-    bool goOn = visitor (value);

-    int32_t count = 1;

-

-    while (goOn) {

-      rc = ::mdb_cursor_get (cur, &mkey, &mval, ::MDB_NEXT_DUP); if (rc == MDB_NOTFOUND) return count;

-      if (rc) throw MdbEx (std::string ("mdb_cursor_get: ") + ::strerror (rc));

-      gstring vstr (0, mval.mv_data, false, mval.mv_size);

-      mdbDeserialize (vstr, value);

-      goOn = visitor (value);

-      ++count;

-    }

-    return count;

-  }

-  /** Iterate over `key` values until `visitor` returns `false`. Return the number of values visited. */

-  template <typename K, typename V> int32_t all (const K& key, std::function<bool(const V&)> visitor) {

-    Transaction txn (beginTransaction (MDB_RDONLY));

-    int32_t count = all (key, visitor, txn);

-    commitTransaction (txn);

-    return count;

-  }

-

-  template <typename K, typename V> bool eraseKV (const K& key, const V& value, Transaction& txn) {

-    char kbuf[64]; // Allow up to 64 bytes to be serialized without heap allocations.

-    gstring kbytes (sizeof (kbuf), kbuf, false, 0);

-    mdbSerialize (kbytes, key);

-    if (kbytes.empty()) throw MdbEx ("eraseKV: key is empty");

-    MDB_val mkey = {kbytes.size(), (void*) kbytes.data()};

-

-    char vbuf[64]; // Allow up to 64 bytes to be serialized without heap allocations.

-    gstring vbytes (sizeof (vbuf), vbuf, false, 0);

-    mdbSerialize (vbytes, value);

-    MDB_val mvalue = {vbytes.size(), (void*) vbytes.data()};

-

-    for (auto& trigger: _triggers) trigger.second->eraseKV (*this, (void*) &key, kbytes, (void*) &value, vbytes, txn);

-

-    int rc = ::mdb_del (txn.get(), _dbi, &mkey, &mvalue);

-    if (rc == MDB_NOTFOUND) return false;

-    if (rc) throw MdbEx (std::string ("mdb_del: ") + ::strerror (rc));

-    return true;

-  }

-  template <typename K, typename V> bool eraseKV (const K& key, const V& value) {

-    Transaction txn (beginTransaction());

-    bool rb = eraseKV (key, value, txn);

-    commitTransaction (txn);

-    return rb;

-  }

-

-  /** Erase all values of the `key`. */

-  template <typename K> bool erase (const K& key, Transaction& txn) {

-    char kbuf[64]; // Allow up to 64 bytes to be serialized without heap allocations.

-    gstring kbytes (sizeof (kbuf), kbuf, false, 0);

-    mdbSerialize (kbytes, key);

-    if (kbytes.empty()) throw MdbEx ("erase: key is empty");

-    MDB_val mkey = {kbytes.size(), (void*) kbytes.data()};

-

-    for (auto& trigger: _triggers) trigger.second->erase (*this, (void*) &key, kbytes, txn);

-

-    int rc = ::mdb_del (txn.get(), _dbi, &mkey, nullptr);

-    if (rc == MDB_NOTFOUND) return false;

-    if (rc) throw MdbEx (std::string ("mdb_del: ") + ::strerror (rc));

-    return true;

-  }

-  /** Erase all values of the `key`. */

-  template <typename K> bool erase (const K& key) {

-    Transaction txn (beginTransaction());

-    bool rb = erase (key, txn);

-    commitTransaction (txn);

-    return rb;

-  }

-

-  static void test (Mdb& mdb) {

-    mdb.add (std::string ("foo"), std::string ("bar"));

-    // NB: "MDB_DUPSORT doesn't allow duplicate duplicates" (Howard Chu)

-    mdb.add (std::string ("foo"), std::string ("bar"));

-    mdb.add ((uint32_t) 123, 1);

-    mdb.add ((uint32_t) 123, 2);

-    mdb.add (C2GSTRING ("foo"), 3);

-    mdb.add (C2GSTRING ("foo"), 4);

-    mdb.add (C2GSTRING ("gsk"), C2GSTRING ("gsv"));

-    string ts; int ti; gstring tgs;

-    auto fail = [](string msg) {throw std::runtime_error ("assertion failed: " + msg);};

-    if (!mdb.first (std::string ("foo"), ts) || ts != "bar") fail ("!foo=bar");

-    if (!mdb.first ((uint32_t) 123, ti) || ti < 1 || ti > 2) fail ("!123");

-    if (!mdb.first (C2GSTRING ("foo"), ti) || ti < 3 || ti > 4) fail ("!foo=3,4");

-    if (!mdb.first (C2GSTRING ("gsk"), tgs) || tgs != "gsv") fail ("!gsk=gsv");

-

-    // Test range-based for.

-    int count = 0; bool haveGskGsv = false;

-    for (auto&& entry: mdb) {

-      if (!entry._key.mv_size || !entry._val.mv_size) fail ("!entry");

-      if (entry.keyView() == "gsk") {

-        if (entry.getKey<gstring>() != "gsk") fail ("getKey(gsk)!=gsk");

-        if (entry.getValue<gstring>() != "gsv") fail ("getValue(gsk)!=gsv");

-        haveGskGsv = true;

-      }

-      ++count;}

-    if (count != 6) fail ("count!=6"); // foo=bar, 123=1, 123=2, foo=3, foo=4, gsk=gsv

-    if (!haveGskGsv) fail ("!haveGskGsv");

-

-    // Test `values`.

-    count = 0; int sum = 0;

-    for (auto&& entry: mdb.valuesRange ((uint32_t) 123)) {

-      if (entry.getKey<uint32_t>() != (uint32_t) 123) fail("values(123).key!=123");

-      ++count; sum += entry.getValue<int>();

-    }

-    if (count != 2) fail ("count(123)!=2");

-    if (sum != 3) fail ("sum(123)!=3");

-

-    if (!mdb.eraseKV ((uint32_t) 123, 1)) fail ("!eraseKV(123,1)");

-    if (!mdb.first ((uint32_t) 123, ti) || ti != 2) fail ("!123=2");

-    if (!mdb.eraseKV ((uint32_t) 123, 2)) fail ("!eraseKV(123,2)");

-    if (mdb.first ((uint32_t) 123, ti)) fail ("123");

-

-    if (!mdb.erase (C2GSTRING ("foo"))) fail ("!erase(g(foo))");

-    if (mdb.first (C2GSTRING ("foo"), ti)) fail ("foo");

-    if (!mdb.erase (std::string ("foo"))) fail ("!erase(str(foo))");

-

-    { // We've erased "123" and "foo", the only key left is "gsk" (gsk=gsv), let's test the iterator boundaries on this small dataset.

-      auto&& it = mdb.begin();

-      if (it->getKey<gstring>() != "gsk") fail ("first key !gsk " + it->keyView().str());

-      if (!(++it).end()) fail ("++it != end");

-      if ((--it)->getKey<gstring>() != "gsk") fail ("can't go back to gsk");

-      if (!(--it).end()) fail ("--it != end");

-      if ((++it)->getKey<gstring>() != "gsk") fail ("can't go forward to gsk");

-    }

-

-    struct SimpleIndexTrigger: public Trigger {

-      const char* _name; Mdb _indexDb;

-      SimpleIndexTrigger (Mdb& mdb, const char* name = "index"): _name (name), _indexDb (mdb._env, name) {}

-      gstring getTriggerName() {return gstring (0, (void*) _name, false, strlen (_name), true);}

-      void add (Mdb& mdb, void* key, gstring& kbytes, void* value, gstring& vbytes, Transaction& txn) {

-        MDB_val mkey = {vbytes.size(), (void*) vbytes.data()};

-        MDB_val mvalue = {kbytes.size(), (void*) kbytes.data()};

-        int rc = ::mdb_put (txn.get(), _indexDb._dbi, &mkey, &mvalue, 0);

-        if (rc) throw MdbEx (std::string ("index, mdb_put: ") + ::strerror (rc));

-      }

-      void erase (Mdb& mdb, void* ekey, gstring& kbytes, Transaction& txn) {

-        // Get all the values and remove them from the index.

-        MDB_cursor* cur = 0; int rc = ::mdb_cursor_open (txn.get(), mdb._dbi, &cur);

-        if (rc) throw MdbEx (std::string ("index, erase, mdb_cursor_open: ") + ::strerror (rc));

-        std::unique_ptr<MDB_cursor, void(*)(MDB_cursor*)> curHolder (cur, ::mdb_cursor_close);

-        MDB_val mkey = {kbytes.size(), (void*) kbytes.data()}, val = {0, 0};

-        rc = ::mdb_cursor_get (cur, &mkey, &val, ::MDB_SET_KEY); if (rc == MDB_NOTFOUND) return;

-        if (rc) throw MdbEx (std::string ("index, erase, mdb_cursor_get: ") + ::strerror (rc));

-        rc = ::mdb_del (txn.get(), _indexDb._dbi, &val, &mkey);

-        if (rc && rc != MDB_NOTFOUND) throw MdbEx (std::string ("index, erase, mdb_del: ") + ::strerror (rc));

-        for (;;) {

-          rc = ::mdb_cursor_get (cur, &mkey, &val, ::MDB_NEXT_DUP); if (rc == MDB_NOTFOUND) return;

-          if (rc) throw MdbEx (std::string ("index, erase, mdb_cursor_get: ") + ::strerror (rc));

-          rc = ::mdb_del (txn.get(), _indexDb._dbi, &val, &mkey);

-          if (rc && rc != MDB_NOTFOUND) throw MdbEx (std::string ("index, erase, mdb_del: ") + ::strerror (rc));

-        }

-      }

-      void eraseKV (Mdb& mdb, void* key, gstring& kbytes, void* value, gstring& vbytes, Transaction& txn) {

-        MDB_val mkey = {vbytes.size(), (void*) vbytes.data()};

-        MDB_val mvalue = {kbytes.size(), (void*) kbytes.data()};

-        int rc = ::mdb_del (txn.get(), _indexDb._dbi, &mkey, &mvalue);

-        if (rc && rc != MDB_NOTFOUND) throw MdbEx (std::string ("index, mdb_del: ") + ::strerror (rc));

-      }

-    };

-    auto indexTrigger = std::make_shared<SimpleIndexTrigger> (mdb); mdb.setTrigger (indexTrigger); auto& indexDb = indexTrigger->_indexDb;

-    mdb.erase (C2GSTRING ("gsk")); // NB: "gsk" wasn't indexed here. `IndexTrigger.erase` should handle this gracefully.

-

-    // Add indexed.

-    mdb.add (C2GSTRING ("ik"), C2GSTRING ("iv1"));

-    mdb.add (C2GSTRING ("ik"), string ("iv2"));

-    mdb.add (C2GSTRING ("ik"), 3);

-    // Check the index.

-    gstring ik;

-    if (!indexDb.first (C2GSTRING ("iv1"), ik) || ik != "ik") fail ("!iv1=ik");

-    if (!indexDb.first (string ("iv2"), ik) || ik != "ik") fail ("!iv2=ik");

-    if (!indexDb.first (3, ik) || ik != "ik") fail ("!iv3=ik");

-

-    // Remove indexed.

-    mdb.eraseKV (C2GSTRING ("ik"), string ("iv2"));

-    // Check the index.

-    if (!indexDb.first (C2GSTRING ("iv1"), ik) || ik != "ik") fail ("!iv1=ik");

-    if (indexDb.first (string ("iv2"), ik)) fail ("iv2=ik");

-    if (!indexDb.first (3, ik) || ik != "ik") fail ("!iv3=ik");

-

-    // Remove indexed.

-    mdb.erase (C2GSTRING ("ik"));

-    // Check the index.

-    if (indexDb.first (C2GSTRING ("iv1"), ik)) fail ("iv1");

-    if (indexDb.first (3, ik)) fail ("iv3");

-    // Check the data.

-    if (mdb.first (C2GSTRING ("ik"), ik)) fail ("ik");

-  }

-

-  virtual ~Mdb() {

-    _triggers.clear(); // Destroy triggers before closing the database.

-    if (_dbi) {::mdb_close (_env.get(), _dbi); _dbi = 0;}

-  }

-};

-

-} // namespace glim

-

-#endif // _GLIM_MDB_HPP_INCLUDED